Conventionally, as a terminal-attached electric wire, the electric wire described in Patent Document 1 (JP2011-82127) is known, for example. The electric wire includes an electric wire including a core wire having a plurality of strand wires, with a terminal crimped onto the core wire exposed from the electric wire. The terminal includes a crimp portion which is crimped so as to wrap around the outside of the core wire. Since the crimp portion is crimped so as to wrap around the outside of the core wire, the electric wire and the terminal are electrically connected. In the manufacturing of the terminal-attached electric wire, prior to crimping the terminal onto the core wire, ultrasonic vibrations are applied to the core wire in order to roughen the surfaces of the strand wires constituting the core wire. When the strand wires with the roughened surfaces are rubbed against each other during the crimping of the terminal, fresh surfaces of the strand wires are exposed, facilitating establishment of electrical connection between the strand wires. As a result, it becomes easier to reduce electrical resistance between the electric wire and the terminal.
However, it has been discovered that, even when ultrasonic vibrations are applied to the core wire prior to crimping the terminal onto the core wire, as in Patent Document 1, the electrical resistance between the electric wire and the terminal may not be sufficiently decreased.
In this case, while the electrical resistance can be decreased by compressing the core wire more during the crimping, excessive compression of the core wire may cause severing of the strand wires constituting the core wire.
Therefore, there is a need in the art to provide a terminal-attached electric wire in which the electrical resistance between the electric wire and the terminal is decreased, and a method for manufacturing a terminal-attached electric wire.